Clampless bottom wiring for electrical devices



Dec. 16; 1952 H. HUBBELL 2,622,119

CLAMPLESS BOTTOM WIRING FOR ELECTRICAL DEVICES Filed May 18, 1950 =mnnm"mm 25 Inventor (F a in W W Gttornegs Patented Dec. 16, 1952 CLAMPLESSBOTTOM WIRING FOR ELECTRICAL DEVICES Harvey Hubbell, Long Hill, Conn.

Application May 18, 1950, Serial No. 162,781

6 Claims.

This invention relates to devices for connecting conductor wires tooutlet receptacles, switches and other electrical elements, and anobject is to provide an improved wire clamping device adapted forgeneral use with such elements.

Heretofore in connecting lead wires to outlet receptacles, for example,it has been customary for the electrician to bend the stripped end ofeach wire to form a loop for embracing the binding post screw and thensecure the looped end under the head of the screw. Such an operation isnot only time consuming, but the resulting connection is not alwaysentirely satisfactory. If the electrician is careless or hurried, thebent loop-may not be properly shaped or sized to be secured correctlyunder the head of the binding screw, or the wire conductor may be ofsuch heavy gauge that the loop cannot be readily formed. In either casethe wire is not engaged and held by the binding screw as securely as isnormally required.

A further object is to eliminate this operation by the electrician andto provide an improved device for connecting conductor wires to electricfixtures, switches and the like constructed and arranged to electricallyand mechanically connect a conductor wire without requiring anypreliminary bending or looping of the stripped conductor.

A further object is to provide an improved device for connecting leadwires to outlet receptacles by back or bottom wiring without clampingthe leads around the binding post screws.

A further object is to provide an improved wire clamping device for usewith outlet receptacles and the like, so constructed as to provide anefficient electrical connection as well :as a strong mechanical gripmerely by inserting the stripped end of a conductor into the device:and' then screwing up on the associated binding With the foregoing andother objects in view,

I have devised the construction illustrated in the accompanying drawingforming a part of this specification. It is, however, to be understoodthe invention is not limited to the specific details of construction andarrangement shown, but may embody various changes and modificationsWithin the scope of the invention.

In this drawing:

Fig. 1 is a side elevation of a duplex electrical outlet receptaclehaving a wire connecting device constructed in accordance with oneembodiment of the invention;

Fig. 2 is a part plan, part horizontal section, of one end of thereceptacle shown in Fig. 1;

Fig. 3 is a vertical transverse section through the lower portion of thereceptacle shown in Figs. 1 and -2;

Fig. 4 is a perspective view showing certain details of the illustratedwire clamp;

Figs. 5, 6 and 7 are views illustrating a detail of the clamping device,and

Fig. 8 is a similar view partly in section of the same detail.

The illustrated embodiment of the invention is shown in connection withan outlet receptacle H, although the invention is equally adapted toother types of electrical devices. As illustrated, the receptacle II isformed of top and bottom sections I2, I3, respectively, of insulatingmaterial and a bottom insulating cover plate M. Spring contacts l5 aremounted in chambers [5a in the bottom section l3 to engage the blades ofattachment plug caps inserted in the slots H1 in the front wall. Theillustrated duplex receptacle includes two sets of such contacts andslots.

Each contact l5 at each end of the receptacle II is connected to adevice for securing a conductor lead thereto. As illustrated, a currentconducting plate It is provided on each side of the receptacle II andhas an inturned flange I! at each end riveted or otherwise connectedelectrically and mechanically to the corresponding contacts l5 on thesame side of the receptacle at each end thereof. Binding screws it arethreaded through threaded openings IS in the plate It; and have slottedscrew heads 2| positioned in recesses 22 formed in the face 23 of thebottom section l3 of insulating material. Each threaded opening I!) maybe re inforced with a threaded collar 24 formed. on or secured to theinner face of they plate 16, if desired.

In order to connect a lead wire to a given contact I5 without anypreliminary shaping or bending, plate It has a plate or flange 25 spacedfrom the plate l6 and connectedto it by a transverse connecting plate 26bent laterally from this plate at the lower edge thereof. The spacedplates I6 and 25 are in planes substantially parallel to each other, andthe plate 25 is so formed as to provide a wire clamping edge 21 on alevel slightly below that of the screw opening [9. As shown in Figs. 4andi'5, the clamping edge 21 is notched,'preferably with a V-shapednotch 28, to adapt it to clamp conductor wires of different gauge, ashereafter explained.

The transverse connecting plate 26 which is shown as located at the backor bottom of the receptacle II has an opening 29 through which thestripped end 3| of a conductor lead or wire 32 can be inserted, theinsulating bottom cover l4 having a corresponding opening 33 concentricwith the opening 29 for this purpose. Assuming the binding screw I8 isretracted so as not to extend across the axis of the opening 29, whenthe stripped end 3| of a conductor 32 is inserted through the alignedopenings 29, 33, it will be located opposite the end 34 of the retractedclamping or binding screw It. By then screwing the latter inwardly theend 34 of the screw, which is relatively blunt, engages theside of thestripped end of the conductor and bends the conductor toward the wall 25of the angle plate and into engagement with the clamping edge 21thereof, the V-shaped notch 28 accommodating wires of difierent gauge.The threads of the screw bite or cut into the wire to increase the gripon the wire and provide a better electrical connection. In order toprevent the rotation of the screw, as it is threaded into the clamp andengages the wire, from causing the wire to be displaced laterally to theside and thus prevented from being properly bent to engage the V notch,the angle plate 6 is formed with a third or guide wall 35 which is sopositioned adjacent the wire as, if necessary, to engage the wire on theside toward which rotation of the screw l8 would tend to displace it, tothereby prevent such displacement and guide the wire into the clampingnotch under the advancing movement of the binding screw l8.

In operation, no preliminary looping or shaping of the conductor lead 32is required, the end 3| thereof merely being stripped of insulation andinserted through the aligned openings 29, 33 to position it between theblunt end 34 of the retracted screw l8 and the clamping edge 2'1, asindicated in dotted lines Fig. 4. Subsequent screwing in of the screwbends the stripped conductor end 3| into engagement with and clamps itagainst the edge 21, the V notch 28 accommodating the clamp to difierentdiameters of wire.

In the illustrated outlet receptacle II, the two receptacle contacts 25at an end of the receptacle will be connected to separate wires 32 and32a, as best shown in Fig. 3, forming the two sides of the circuit. Amounting bridge 33 extends longitudinally of the receptacle H and hasears 39 for securing the receptacle to any suitable supporting surface.

The invention can be variously modified and adapted within the scope ofthe appended claims.

Having thus set forth the nature of my invention, I claim:

1. An electric fixture having a body of insulating material formed witha recess opening at the back and side of said body, an electric contactin said body, a Wire clamp electrically connected to said contactmounted in said recess and including an angle plate having one wall atthe back of said recess and formed with an opening adapted to receivethe stripped end of a conductor wire, a second wall at substantiallyright angles to the first wall and located at one side of said recess,and a third wall substantially parallel to the second wall and locatedon the opposite side of said opening from this wall so that the openingis located between the second and third walls, said third wall beingprovided with a wire clamping edge, and a binding screw threaded throughsaid second wall above the first wall to engage one side of the strippedend of a conductor wire projecting into said recess through said openingto bend said wire laterally and clamp it against said clamping edge.

2. An electric fixture having a body of insulating material formed witha recess opening at the back and side of said body, an electric contactin said body, a wire clamp electrically connected to said contact membermounted in said recess and including an angle plate having one wall atthe back of said recess and formed with an open- Iing adapted to receivethe stripped end of a conductor wire, a second wall at substantiallyright angles to the first wall and located at one side of said recess,and a third wall at substantially right angles to the first wall andlocated on the opposite side of the opening from the second wall, saidthird wall having a wire receiving V-shaped notch in the edge thereofopposite said second wall, and a binding screw threaded through saidsecond wall above the first wall to engage one side of the stripped endof a conductor wire projecting into said recess through said opening tobend said wire laterally and clamp it in engagement with said V-notch.

3. An electric fixture having a body of insulating material formed witha recess opening at the back and side ofsaid body, an electric contactin said body, a wire clamp electrically connected to said contact membermounted in said recess and including an angle plate having one wall atthe back of said recess and .formed with an opening adapted to receivethe stripped end of a conductor wire, a second wall at substantiallyright angles to the first wall and located at one side of said recess,and a third wall forming a wire clamping edge, located at the oppositeside of said opening from the second wall, a binding screw threadedthrough said second Wall above the first wall to engage one side of thestripped end of a conductor wire projecting into said recess throughsaid opening to bend said wire in a direction longitudinally of thescrew and clamp it against said clamping edge, and a guide wall locatedat one side of the screw to prevent lateral displacement of said Wirewhen engaged by said screw whereby to guide the bent end of said wireagainst said clamping edge.

4. An electric fixture having a body of insulating material formed witha recess opening at the back and side of said body, an electric contactin said body, a wire clamp electrically connected to said contact membermounted in said recess and including an angle plate having one wall atthe back of said recess and formed with an opening adapted to receivethe stripped end of a conductor wire, a second wall extending at anangle to the first wall and located at one side of said recess, and athird wall formed with a wire clamping edge located at the opposite sideof said opening from the second wall, and a binding screw threadedthrough said second wall above the first wall to engage one side of thestripped end of a conductor wire projecting into said recess throughsaid opening to bend said wire in a direction longitudinally of thescrew and clamp it against said clamping edge, and a guard memberlocated at one side of the screw for guiding the stripped end of saidwire into engagement with said clamping edge as it is bent by operationof said screw.

5. The combination in an electrical device having an electrical contact,of means for connecting a wire to said contact comprising spacedsubstantially parallel plates electrically connected to said contact,one of said plates having a clamping edge, means for positioning aconductor wire between said plates with its axis substantially parallelto the planes of said plates comprising a third plate extendin betweenand connecting the first two plates and provided with an opening for theconductor wire leading to the space between said plates, and a clampingscrew threaded through the second of said plates into said space formovement transverse to said wire to engage one side of and bend saidwire toward said clamping edge and clamp the bent portion against saidedge.

6. The combination in an electrical device having an electrical contact,of means for connecting a wire to said contact comprising spacedsubstantially parallel plates electrically connected to said contact,one of said plates having a clamping edge positioned substantiallyopposite a threaded opening in the other plate, a third plate extendingbetween and connecting the first plates provided with an opening leadingto the space HARVEY HUBBELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,830,466 Hines Nov. 3, 1931FOREIGN PATENTS Number Country Date 734,046 France July 25, 1932

